Fister was neutered at the age of 1, but you know he had problems with struvite crystals and ended up getting his bits chopped off. However, he's been fine since then.

You may want to put him on a diet which dissolve crystals, if that is part of the problem.

One thing I've heard is, that they can get all sorts of problems, if they're taken from their mom too early. How old was Pichu when you got him?

Sorry I can't be of much help here.

Good to see you here anyway!